Yes all those services work fine for withdrawing without currency conversion then offer a decent rate when bringing the money back home.
You just have to watch out for charges when paying suppliers, as you might think if you have USD10,000 in the account you can pay a supplier that without charge like you could with an ordinary bank account.
These services are competing hard against each other so I would check if Payoneer can do that now. Sometimes they let you pay suppliers, but only in a roundabout way because they still want to make their margin on you effectively withdrawing funds.
I believe Payoneer quote 2% above mid-market rates. With WorldFirst and CurrenciesDirect you have to login to check rates, last time I looked.